see also: [[Liver Failure]], [[Needlestick injury]] see: [Cameron - Hepatitis](x-devonthink-item://05082D11-9127-41D1-95F0-49EF3B1CF19A?page=26) #incomplete ## Causes - Hepatitis A-E - CMV (milder disease) - EBV (milder disease) - Toxoplasmosis ## Viral Hepatitis **Hep A** – faecal oral route (oral/anal sex, injecting/ non-injecting drug use) - nil chronic phase **Hep B** – blood borne (unprotected sex, IV sharing, mother-to-baby, pre-1971 blood products) Tx, 2-26wks incubation 90% infant infections become chronic. 5-10% adult infections become chronic  **Hep C** – blood borne  (pre-1990 blood products) Tx, 2-26wks incubation 50-80% become chronic (25% cirrhosis) **Hep D** - blood borne. normally suprainfection of Hep B **Hep E** - faecal-oral. serious in pregnant women (nil chronic) ## Hepatitis B ![[Pasted image 20251016094903.png]] **HBsAg (hepatitis B surface antigen)** _is the first serologic marker to appear in a new acute infection,_ which can be detected as early as 1 week and as late as 9 weeks, with an average of one month after exposure to the hepatitis B virus (HBV).  -  detectable for a variable amount of time, along with the HBV DNA, though about 50% of persons will test HBsAg and HBV DNA negative 7 weeks after symptoms. - All persons who spontaneously recover from an infection will test negative for HBsAg and negative for HBV DNA about 15 weeks after the appearance of symptoms **Anti-HBs or HBsAb (hepatitis B surface antibody)** – this becomes detectable on a blood test after the disappearance of HBsAg in persons who are able to get rid of the virus and avoid a chronic infection. The presence of anti-HBs following a new acute infection generally indicates recovery and a person is then protected (or “immune”) from re-infection with hepatitis B **Anti-HBc or HBcAb (hepatitis B core antibody)** _**–**_ this blood test remains positive indefinitely as a marker of past HBV infection **- IgM anti-HBc** – a positive blood test result indicates a person has a new acute hepatitis B infection. IgM anti-HBc is generally detectable at the time symptoms appear and declines to sub-detectable levels within 6 - 9 months. Note: An acute exacerbation (or liver flare) in a chronic HBV infection can also result in a positive anti-HBc IgM test result. So follow-up testing after 6 months is required **- IgG anti-HBc** _–_ this blood test remains positive indefinitely as a marker of past HBV infection **HBeAg** **(hepatitis B e-antigen)** is generally detectable in patients with a new acute infection; the presence of HBeAg is associated with higher HBV DNA levels, thus, increased infectiousness ![[Pasted image 20251016094431.png]] ![[Pasted image 20251016094827.png]]